Apparatus and method for maintaining controlled orientation of a roller lifter follower used in conjunction with a variable phased lifter
In a variable phased valve lifter of an internal combustion engine, two or more roller lifter are allowed to move along constraining faces of a constraining mechanism in a first direction, and the constraining mechanism is allowed to move freely in a second direction. As the roller lifters move through their parallel arcuate paths, the engaging surface(s) of the roller lifters will engage with the constraining face(s) of the constraining mechanism, and each roller lifter will prevent the other from rotating about its longitudinal axis. The roller lifter is thus prevented from rotating about its longitudinal axis as it moves in arcuate fashion in cooperation with the constraining mechanism.
Latest Motive Engineering Co. Patents:
This invention relates to an internal combustion engine using poppet type valves to direct gases into and out of one or more cylinders or cam operated fuel injection units to inject fuel into one or more cylinders. More particularly, the orientation of a roller lifter follower in a pushrod operated engine is to be kept constant during rotation of a rotatable element to alter the phasing of the valves or injectors in the engine.
BACKGROUND OF THE INVENTIONA description of a phasing system for roller lifter followers on a camshaft is given by Riley in U.S. Pat. No. 6,155,216, which is hereby incorporated by reference for all that is taught and disclosed therein. A description of means to maintain orientation of a roller lifter used in conjunction with a variable phase lifter is given by Riley in U.S. Pat. No. 6,932,041, which is hereby incorporated by reference for all that is taught and disclosed therein.
As the rotatable element, such as an eccentric sleeve, is rotated to phase the roller lifter follower (hereinafter simply “roller lifter”), the roller lifter orientation must be controlled to allow the roller to follow the cam lobe on the camshaft. In fixed timing systems a simple pin or plate is usually sufficient to prevent the roller lifter from rotating around its longitudinal axis during operation. The arcuate path of the phased roller lifter requires an extra degree of freedom of movement. Therefore additional measures must be taken in order to maintain controlled orientation of the roller lifter.
SUMMARY OF THE INVENTIONThe present invention describes a simple system for providing controlled orientation of two or more roller lifters in a pushrod engine using a phasing device to change the point of contact of the roller lifters on the cam. It also applies to roller lifters that may have curved surfaces for contacting the cam, but may not have rollers.
A description of the need for controlled orientation of roller lifters is given in U.S. Pat. No. 6,932,041. In the present invention roller lifters with the same motion caused by rotation of their respective eccentric sleeves are allowed to move through their arcuate paths, with the orientation mechanism also following the same path in one embodiment. The orientation mechanism may be located in a direction parallel to the axis of the lifter, but it is free to move in the plane perpendicular to that direction. In one embodiment the orientation mechanism will fit snugly over each lifter, as it is the action of two or more moving lifters acting on the orientation mechanism that provides the means of orientation for the other lifter(s). In another embodiment the orientation mechanism need not fit snugly, but is free to slide in a direction parallel to the orienting surfaces on the lifters.
Referring now to the Figures, in which like reference numerals refer to like components thereof,
One skilled in the art will recognize that roller lifters 12a and 12b could each have just one flat surface 14a and 14b, and corresponding constraining mechanism 15 would have within apertures 17a and 17b only one flat surface 18a and 18b. Also, the flat surfaces 14a/14b for one roller lifter 12a/12b and flat surfaces 18a/18b for apertures 17a/17b could be on the same side in relation to each other, or on opposite sides in relation to each other.
Having described the present invention, it will be understood by those skilled in the art that many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the scope of the present invention.
Claims
1. A method for controlling the orientation of at least two roller lifters in an internal combustion engine having at least two rotatable elements that eccentrically move the at least two roller lifters to alter the phasing of the at least two roller lifters engaging with a cam, the method comprising the steps of:
- (a) receiving the at least two roller lifters in at least two apertures of a constraining mechanism;
- (b) rotating the at least two rotatable elements that eccentrically move the at least two roller lifters;
- (c) allowing by said constraining mechanism the at least two roller lifters to move in a direction parallel to each of their respective longitudinal axes; and
- (d) preventing by said constraining mechanism each of the at least two roller lifters from rotating about each of their said respective longitudinal axes;
- wherein each point on said constraining mechanism moves through a same parallel arcuate path as the at least two roller lifters.
2. The method according to claim 1 wherein step (a) further comprises the step of:
- engaging at least one flat surface of said at least two apertures of said constraining mechanism with a corresponding at least one flat surface of each of said at least two roller lifters.
3. The method according to claim 1 wherein step (a) further comprises the step of:
- engaging at least one curved surface of said at least two apertures of said constraining mechanism with a corresponding at least one curved surface of each of said at least two roller lifters.
4. The method according to claim 1 wherein step (a) further comprises the step of:
- fitting closely said at least two apertures of said constraining mechanism to a corresponding exterior circumferential shape of the at least two roller lifters.
5. The method according to claim 1 wherein step (a) further comprises the steps of:
- engaging closely at least two flat parallel surfaces of said at least two apertures of said constraining mechanism with a corresponding at least two flat parallel surfaces of each of said at least two roller lifters; and
- fitting loosely at least two surfaces perpendicular to said at least two flat parallel surfaces of said at least two apertures with a perpendicular other surfaces of the at least two roller lifters.
6. The method according to claim 1 wherein step (a) further comprises the step of:
- aligning closely at least one feature on each of the at least two roller lifters with said at least two apertures of said constraining mechanism, wherein said at least one feature is parallel with said respective longitudinal axes.
7. The method according to claim 6 wherein said aligning step further comprises the step of:
- aligning a flat surface on each of the at least two roller lifters with a corresponding flat surface on each of said at least two apertures of said constraining mechanism.
8. The method according to claim 6 wherein said aligning step further comprises the step of:
- aligning at least two flat parallel surfaces on each of the at least two roller lifters with a corresponding at least two flat parallel surfaces on each of said at least two apertures of said constraining mechanism.
9. The method according to claim 6 wherein said aligning step further comprises the step of:
- aligning at least two flat surfaces that are at an angle to each other on each of the at least two roller lifters with a corresponding at least two flat surfaces that are at said angle to each other on each of said at least two apertures of said constraining mechanism.
10. The method according to claim 6 wherein said aligning step further comprises the step of:
- aligning a longitudinal slot on each of the at least two roller lifters with a corresponding tang in each of said at least two apertures of said constraining mechanism.
11. The method according to claim 6 wherein said aligning step further comprises the step of:
- aligning an arbitrary or irregular circumferential geometry on each of the at least two roller lifters with an identical arbitrary or irregular circumferential geometry of each of said at least two apertures of said constraining mechanism.
12. The method according to claim 1 further comprising the step of:
- constraining movement of said constraining mechanism in a direction parallel to said longitudinal axes while allowing said constraining mechanism to move freely in a direction perpendicular to said longitudinal axes.
13. The method according to claim 1 further comprising the step of:
- forming an arcuate fastener slot in said constraining mechanism, said arcuate fastener slot being shaped parallel to the paths that said longitudinal axes follow when moved by the at least two rotatable elements;
- attaching a block to a structure containing the at least two rotatable elements; and
- inserting a fastener through said arcuate fastener slot and into said block.
14. The method according to claim 1 further comprising the step of:
- attaching a block to a structure containing the at least two rotatable elements; and
- extending a tab over said constraining mechanism; and
- inserting a fastener through said tab and into said block.
15. The method according to claim 1 further comprising the step of:
- not receiving a third roller lifter located between the at least two roller lifters in said constraining mechanism through an extension member that does not touch said third roller lifter, allowing said third roller lifter to orient independently about its longitudinal axis and not said longitudinal axes of the at least two roller lifters.
16. An apparatus in an internal combustion engine having at least two rotatable elements that eccentrically move at least two roller lifters to alter the phasing of the at least two roller lifters engaging with a cam, the apparatus comprising:
- a constraining mechanism having at least two apertures, wherein each of said at least two apertures receives a one of the at least two roller lifters;
- wherein as the at least two rotatable elements eccentrically move the at least two roller lifters, said constraining mechanism allows each of the at least two roller lifters to move freely in a direction parallel to each of their respective longitudinal axes, and prevents each of the at least two roller lifters from rotating about each of their said respective longitudinal axes, and further wherein each point on said constraining mechanism moves through a same parallel arcuate path as the at least two roller lifters.
17. The apparatus according to claim 16 wherein said at least two apertures of said constraining mechanism further comprises at least one flat surface, wherein each of said at least one flat surface engages with a corresponding at least one flat surface of each of said at least two roller lifters.
18. The apparatus according to claim 17 wherein said at least two apertures of said constraining mechanism further comprises at least one curved surface, wherein each of said at least one curved surface engages with a corresponding at least one curved surface of each of said at least two roller lifters.
19. The apparatus according to claim 17 wherein said at least two apertures of said constraining mechanism fit closely to a corresponding exterior circumferential shape of the at least two roller lifters each received in said at least two apertures.
20. The apparatus according to claim 16 wherein said at least two apertures of said constraining mechanism further comprises at least two flat parallel surfaces, wherein each of said at least two flat parallel surfaces engages with a corresponding at least two flat parallel surfaces of each of said at least two roller lifters, wherein said at least two flat parallel surfaces of said at least two apertures of said constraining mechanism fit closely respectively with said at least two flat parallel surfaces of said at least two roller lifters, and said at least two surfaces perpendicular to said at least two flat parallel surfaces of said at least two apertures fit loosely over a perpendicular other surfaces of the at least two roller lifters.
21. The apparatus according to claim 16 further comprising:
- at least one feature on each of the at least two roller lifters that closely aligns with said at least two apertures of said constraining mechanism, wherein said at least one feature is parallel with said respective longitudinal axes.
22. The apparatus according to claim 21 wherein said at least one feature on each of the at least two roller lifters is a flat surface.
23. The apparatus according to claim 21 wherein said at least one feature on each of the at least two roller lifters is at least two flat surfaces, wherein said at least two flat surfaces are parallel to each other.
24. The apparatus according to claim 21 wherein said at least one feature on each of the at least two roller lifters is at least two flat surfaces, wherein said at least two flat surfaces are at an angle to each other.
25. The apparatus according to claim 21 wherein said at least one feature on each of the at least two roller lifters is a longitudinal slot that mates with a tang in each of said at least two apertures of said constraining mechanism.
26. The apparatus according to claim 21 wherein said at least one feature on each of the at least two roller lifters is an arbitrary or irregular circumferential geometry that mates with an identical arbitrary or irregular circumferential geometry of each of said at least two apertures of said constraining mechanism.
27. The apparatus according to claim 16 further comprising:
- a means for constraining movement of said constraining mechanism in a direction parallel to said longitudinal axes while allowing said constraining mechanism to move freely in a direction perpendicular to said longitudinal axes.
28. The apparatus according to claim 16 further comprising:
- an arcuate fastener slot in said constraining mechanism, said arcuate fastener slot being shaped parallel to the paths that said longitudinal axes follow when moved by the at least two rotatable elements;
- a block that is part of a structure containing the at least two rotatable elements; and
- a fastener inserted though said arcuate fastener slot and into said block;
- wherein said fastener, said arcuate fastener slot, and said block constrain said constraining mechanism from movement in a direction parallel to said longitudinal axes while allowing said constraining mechanism to move freely in a direction perpendicular to said longitudinal axes.
29. The apparatus according to claim 16 further comprising:
- a block that is part of a structure containing the at least two rotatable elements;
- a tab which extends over said constraining mechanism; and
- a fastener inserted through said tab and into said block;
- wherein said fastener, said tab, and said block constrain said constraining mechanism from movement in a direction parallel to said longitudinal axes while allowing said constraining mechanism to move freely in a direction perpendicular to said longitudinal axes.
30. The apparatus according to claim 16 wherein said constraining mechanism further comprises:
- an extension member, wherein a third roller lifter located between the at least two roller lifters is not captured by said constraining mechanism, allowing said third roller lifter to orient independently about its longitudinal axis and not said longitudinal axes of the at least two roller lifters.
4089234 | May 16, 1978 | Henson et al. |
5022356 | June 11, 1991 | Morel, Jr. et al. |
5263386 | November 23, 1993 | Campbell et al. |
5546899 | August 20, 1996 | Sperling et al. |
5934232 | August 10, 1999 | Greene et al. |
5947069 | September 7, 1999 | Koerner |
6155216 | December 5, 2000 | Riley |
6209498 | April 3, 2001 | Brothers |
6257189 | July 10, 2001 | Moertz et al. |
6357407 | March 19, 2002 | Brothers |
6736097 | May 18, 2004 | Riley |
6932041 | August 23, 2005 | Riley |
20040065282 | April 8, 2004 | Riley |
- Lee W. Young, Notification of Transmittal of the International Search Report and the Written Opinion of the International Searching Authority, or the Declaration, Oct. 30, 2007.
Type: Grant
Filed: Nov 30, 2005
Date of Patent: Aug 12, 2008
Patent Publication Number: 20070119398
Assignee: Motive Engineering Co. (Fort Collins, CO)
Inventor: Michael Bernard Riley (Fort Collins, CO)
Primary Examiner: Ching Chang
Attorney: Merchant & Gould PC
Application Number: 11/290,726
International Classification: F01P 11/20 (20060101);